Conditional breakpoints in Visual Studio

You can specify a breakpoint condition which will be evaluated when a breakpoint is reached. The debugger will break only if the condition is satisfied.

To specify a condition:

In a source window, right-click a line containing a breakpoint glyph and choose Condition from Breakpoints in the shortcut menu.
In the Breakpoint Condition dialog box, define a boolean condition using the code in your local scope. For example, you can only break when _culture != "en-US".
Choose Is true if you want to break when the expression is satisfied or Has changed if you want to break when the value of the expression has changed.
Click OK.